implemented extraction of signature timestamp to fix some playback is…

…sues

Sources/YouTubeKit/Extraction.swift

@@ -112,6 +112,18 @@ class Extraction {
         return (nil, [nil])
     }
 
+    /// Extracts the signature timestamp (sts) from javascript. 
+    /// Used to pass into InnerTube to tell API what sig/player is in use.
+    /// - parameter js: The javascript contents of the watch page
+    /// - returns: The signature timestamp (sts) or nil if not found
+    class func extractSignatureTimestamp(fromJS js: String) -> Int? {
+        let pattern = NSRegularExpression(#"(?:signatureTimestamp|sts)\s*:\s*([0-9]{5})"#)
+        if let match = pattern.firstMatch(in: js, group: 1) {
+            return Int(match.content)
+        }
+        return nil
+    }
+
     /// Parses input html to find the end of a JavaScript object.
     /// - parameter html: HTML to be parsed for an object.
     /// - parameter precedingRegex: Regex to find the string preceding the object.

Sources/YouTubeKit/InnerTube.swift

@@ -72,14 +72,17 @@ class InnerTube {
     private let context: Context
     private let headers: [String: String]
     private let playerParams: String
+
+    private let signatureTimestamp: Int?
 
     private let baseURL = "https://www.youtube.com/youtubei/v1"
 
-    init(client: ClientType = .ios, useOAuth: Bool = false, allowCache: Bool = true) {
+    init(client: ClientType = .ios, signatureTimestamp: Int?, useOAuth: Bool = false, allowCache: Bool = true) {
         self.context = defaultClients[client]!.context
         self.apiKey = defaultClients[client]!.apiKey
         self.headers = defaultClients[client]!.headers
         self.playerParams = defaultClients[client]!.playerParams ?? "8AEB"
+        self.signatureTimestamp = signatureTimestamp
         self.useOAuth = useOAuth
         self.allowCache = allowCache
 
@@ -205,17 +208,27 @@ class InnerTube {
         }
     }
 
+    private struct PlaybackContext: Encodable {
+        let contentPlaybackContext: Context
+
+        struct Context: Encodable {
+            let html5Preference = "HTML5_PREF_WANTS"
+            let signatureTimestamp: Int?
+        }
+    }
+
     private struct PlayerRequest: Encodable {
         let context: Context
         let videoId: String
         let params: String
-        //let paybackContext
+        let paybackContext: PlaybackContext
         let contentCheckOk: Bool = true
         let racyCheckOk: Bool = true
     }
 
     private func playerRequest(forVideoID videoID: String) -> PlayerRequest {
-        PlayerRequest(context: context, videoId: videoID, params: playerParams)
+        let playbackContext = PlaybackContext(contentPlaybackContext: PlaybackContext.Context(signatureTimestamp: signatureTimestamp))
+        return PlayerRequest(context: context, videoId: videoID, params: playerParams, paybackContext: playbackContext)
     }
 
     func player(videoID: String) async throws -> VideoInfo {

Sources/YouTubeKit/YouTube.swift

@@ -23,6 +23,7 @@ public class YouTube {
     private var _embedHTML: String?
     private var playerConfigArgs: [String: Any]?
     private var _ageRestricted: Bool?
+    private var _signatureTimestamp: Int?
 
     private var _fmtStreams: [Stream]?
 
@@ -188,6 +189,17 @@ public class YouTube {
             return _js!
         }
     }
+
+    var signatureTimestamp: Int? {
+        get async throws {
+            if let cached = _signatureTimestamp {
+                return cached
+            }
+
+            _signatureTimestamp = try await Extraction.extractSignatureTimestamp(fromJS: js)
+            return _signatureTimestamp!
+        }
+    }
 
     /// Interface to query both adaptive (DASH) and progressive streams.
     /// Returns a list of streams if they have been initialized.
@@ -316,11 +328,13 @@ public class YouTube {
                     return nil
                 }
             }
+
+            let signatureTimestamp = try await signatureTimestamp
 
             let innertubeClients: [InnerTube.ClientType] = [.ios, .mWeb]
 
             let results: [Result<InnerTube.VideoInfo, Error>] = await innertubeClients.concurrentMap { [videoID, useOAuth, allowOAuthCache] client in
-                let innertube = InnerTube(client: client, useOAuth: useOAuth, allowCache: allowOAuthCache)
+                let innertube = InnerTube(client: client, signatureTimestamp: signatureTimestamp, useOAuth: useOAuth, allowCache: allowOAuthCache)
 
                 do {
                     let innertubeResponse = try await innertube.player(videoID: videoID)
@@ -363,7 +377,8 @@ public class YouTube {
     }
 
     private func loadAdditionalVideoInfos(forClient client: InnerTube.ClientType) async throws -> InnerTube.VideoInfo {
-        let innertube = InnerTube(client: client, useOAuth: useOAuth, allowCache: allowOAuthCache)
+        let signatureTimestamp = try await signatureTimestamp
+        let innertube = InnerTube(client: client, signatureTimestamp: signatureTimestamp, useOAuth: useOAuth, allowCache: allowOAuthCache)
         let videoInfo = try await innertube.player(videoID: videoID)
 
         // ignore if incorrect videoID
@@ -376,7 +391,8 @@ public class YouTube {
     }
 
     private func bypassAgeGate() async throws {
-        let innertube = InnerTube(client: .tvEmbed, useOAuth: useOAuth, allowCache: allowOAuthCache)
+        let signatureTimestamp = try await signatureTimestamp
+        let innertube = InnerTube(client: .tvEmbed, signatureTimestamp: signatureTimestamp, useOAuth: useOAuth, allowCache: allowOAuthCache)
         let innertubeResponse = try await innertube.player(videoID: videoID)
 
         if innertubeResponse.playabilityStatus?.status == "UNPLAYABLE" || innertubeResponse.playabilityStatus?.status == "LOGIN_REQUIRED" {